Heater cut-out for electric lamps.



No. 728,821. PATENTED MAY 19, 1903. A. J. WURTS. HEATER GUT-OUT FORELECTRIC LAMPS.

APPLICATION FILED MAR. 14. 1901. RENEWED we. 4, 1902. NO MODEL.

Fig. 71

75 WITNESSES: a INVENTOR A TOR/V5 r.

UNiTED STATES Patented May 19, 1903.

PATENT Genres.

ALEXANDER JAY WURTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO GEORGEVVES'IINGHOUSE, OF PI'ITSBURG, PENNSYLVANIA.

HEATER CUT-OUT FOR ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 728,821, dated May 19,1903;

Application filed March 14, 1901. Renewed August 4:, 1902. serial No.118,380. (No model.)

To all whom it may concern:

Beitknown that LALEXANDERJAYWURTS, a citizen of the UnitedStates,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in HeaterCut-Outs for Electrio Lamps, of which the following is a specification.

My invention relates to.electric lamps of the type in which thelight-giving body or glower is a non-conductor when cold and is raisedto conducting temperature by means of an electric heater located inproximity thereto.

My invention relates more particularly to devices employed forautomatically opening the circuit of the electric heater when the glowerbecomes conductive and for automatically closing such circuit when theglower is not taking current either by reason of its being in anon-conducting state or by reason of its circuit being open.

The object of my invention is to provide a cut-out orcircuit-interrupting device that shall be actuated. by gravity to closethe circuit and by magnetism to open it, that shall be effective anddurable in operation, and that shall be substantially noiseless whenused in lamps operated by alternating currents. In order to accomplishthis object, I have devised a cutout the movable member of which has asingle point of pivotal support and has its center of gravity below suchpoint of support in all its operating positions.

In the accompanying drawings, Figure 1 is a view, partially in sideelevation and partially in section, of one form of cut-out embodying myinvention, the other members of the lamp and the circuits beingdiagrammatically indicated. Fig. 2 is a view, partially in plan andpartially in section, of the movable member of the cut-out and itssupporting-pivot shown in Fig. 1. Fig. 3, is a view, partially insection and partially in end elevation, of the cut-out shown in Fig. 1.Figs. 4 and 5 are detail views showing modified forms of support for themovable member of the cut-out.

Referring now to Figs. 1, 2, and 3, the glower 1, heater 2, and ballast3 may have any wellknown and suitable construction and arrange- I ment,the glower and ballast being connected in series with each other andwith a cut-out coil h'which has a core 5 projecting downwardly beyondthe end of the coil and is supported, by means of a bracket 6, upon asuitable non-conducting base 7. The base 7 also supports two terminalposts-8, to which are respectively connected by any suitable bind ingmeans the terminals of the heater-circuit. Projecting inwardly throughholes formed in the studs 8 are wires 9, preferably, though notnecessarily, made of silver, the inner ends of which are bent downward,so as to form a V- shaped space between them, into which the movablemember 10 of the cut-out drops by gravity action when the cut-out coil 4is deenergized. The movable member 10, as shown, comprises acomparatively thin strip 11, on which are fitted three blocks 12, 13,and 14, the block 13 being preferably made of or coated with silver andso located as to engage the silver wires 9 to close the heatercircuitand the other collars or blocks being made of magnetizable material. Thestrip 11 may be of. steel or other suitable material and, as shown inFig. 1, it is curved upwardly beyond the block 14 and is supported upona pin 15, the ends of which are mounted in the arms of asuitablebracketor standard 16. In order to maintain the movable member 10 in acentral position, the pin 15 may be tapered from both ends inwardly tothe middle or otherwise formed, so as to present an approximatelyV=shaped formation in longitudinal section, the diameter of the pin atthe apex'of the V being less than that of the hole 17 in the piece 11.The periphery of the opening 17 of the'piece 11 preferably has aknife-edge contour, so that it engages the pin 15 at a single pointonly. I have shown the piece 11 as provided with a cut or slit 18 at oneside, so that the adjacent parts may be sprung away from each other inorder to slip the device over the pin 15; but of course this featuremight be omitted and the pin inserted through the opening 17 beforeseating its ends in the arms of the bracket 16. I have found itconvenient to employ a steel strip 11, that is so thin as to present asufficiently close approximation to with the source of current.

aknife-edg'e by merely cutting the hole 17 therein. This feature as wellas certain of the others are, however,.subject to variations, all ofwhich it would be impracticable to illustrate.

In Figs. l and 5 I have shown one modification in which thesupporting-pin l5 for the movable member of the cut-out is a wire theends of which are inserted in slots or sockets 19 in the arms of thebracket 16 and clamped in position by upsetting the adjacent metal ofthe bracket-arms. Between the two bracket-arms the wire is shown as bentinto a V shape. This form is illustrated merely to indicate a simple andinexpensive variation from what is shown in the preceding figureswithout any intention of excluding from the scope of the invention anyother forms of pivotal support for the armature that might be employedto permit freedom of movement under the actions of magnetism and gravityand at the same time permitlateral displacement along the pivot.

In operation the current first traverses the heater 2, the stationarycontact-terminals 8 9, the bridging member 10, and the wires whichconnect these devices with each other and As soon as the glower 1 isheated to conducting temperature current flows through it, the ballastdevice 3, and magnet-coil 4, and the magnetic field produced by thelatter lifts the armature 10 from the contact-terminals 9 and holds itin this position so long as the glower remains conductive. When the lampis operated by means of an alternating current, the alternations tend toproduce vibrations of the armature and a resulting humming noise that isobjectionable. As here shown, however, the armature is so constructedand supported that its center of gravity is always below its singlepoint of support, and consequently gravity acts throughout eachalternation to hold the armature upon its support. The chattering orhumming noise which ordinarily results from the intermittent pull oflowfrequency currents is thus avoided.

As I have already stated, my inventionis susceptible of embodiment inapparatus that differs from what is shown in the drawings as regardsform, dimensions, and relative location of parts without modifying themode of operation or result. I therefore do not intend to limitmyinvention except in so far as limitations are imposed by the prior artand expressed in the claims.

I claim as my invention- 1. Ina heater cut-out for electric lamps, thecombination with a cut-out coil, of adjacent, convergingheater-terminals and a cooperating pivoted oontact-terminal having aknife-edge support and operated in one direction by the magnet and inthe other direction by gravity and having its center of gravity belowits point of support.

2. In a cut-out, the combination with an electromagnet an armaturetherefor serving as the movable member of the cut-out, convergingcontact-terminals and means for pivotally supporting the movable memberabove said terminals at a single point and with its center of gravitybelow said point.

3. In a heater cut-out for electric lamps, the combination with anactuating-magnet, of stationary contact-terminals, an armature servingto bridge said terminals when the magnet is deenergized and means forpivotally supporting the armature at asingle point.

at. In a heater cut-out for electric lamps, the combination with anactuating-magnet, of heater circuit-terminals and an armature for makingand breaking the circuit at said terminals, said armature beingpivotallysupported at a single point and having its center of gravitybelow the point of support.

5. In a heater cut-out for electric lamps, the combination with anactuating-magnet, converging heater circuit-terminals, and an armaturehaving a pivotal support above said terminals and its center of gravitybelow said support in all of its operative positions, said armaturebeing moved by magnetism away from said circuit-terminals and by gravityinto engagement therewith.

6. In a heater cut-out for electric lamps, the combination with anactuating-magnet, of stationary heater-terminals, an armature for makingand breaking the circuit at said terminals and a support upon which saidarmature is pivotally mounted by means of a knife-edge bearing.

7. In a heater cut-out for electric lamps, the combination with anactuating-magnet, of heater circuit-terminals and a combined armatureand cut-out member havingaknifeedge hearing at a single point and havingits center of gravity below said point of support in all its operatingpositions.

In testimony whereof I have hereunto subscribed my name this 11th day ofMarch, 1901.

ALEXANDER JAY WURTS. Witnesses:

H. A. ORooKs, D. W. CRooKs.

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